The invention relates to polymerizable esters of acrylic or methacrylic acid with polyhydric phenols and to a process for their preparation.
Monoacrylates and monomethacrylates of dihydric phenols are described in German Offenlegungsschrift No. 1,933,657 and No. 2,659,809. They are prepared by reacting dihydric phenols with for example acryloyl or methacryloyl chloride. The resulting reaction mixtures, in addition to unreacted starting compounds, contain monoacylated and diacylated phenols which can only be separated with difficulty and with yield losses. The isolated monoesters generally still contain the indicated impurities and are obtained in yields which, as a whole, are significantly below 50%, based on the starting materials. The impurities due to compounds having more than one polymerizable ester group in the molecule can lead to considerable difficulties in the further processing of the compounds to polymers, since they give rise to branched and, possibly, cross-linked polymers which have completely different solubility and viscosity properties than linear polymers.